Abstract: In a power plant having a boiler for heating a fluid to form a gaseous phase, a power generator for generating electrical power from the gaseous phase, a condenser for condensing the gaseous phase after the gaseous phase has passed through the power generator, a liquid ring pump for evacuating uncondensed gaseous phase from the condenser, and a chiller for cooling seal liquid discharged from the liquid ring pump for re-use in the liquid ring pump, apparatus is provided for utilizing the heat generated during the operation of the chiller to heat a predetermined portion of the fluid supplied to the boiler, thereby reducing the amount of heat which must be provided by the boiler to form a gaseous phase of the fluid so that electricity can be generated. The efficiency of the power plant is thereby increased.